CVE-2025-64011: Nextcloud Server 30.0.0 is vulnerable to an Insecure Direct Object Reference (IDOR) in the /core/preview endpoint. Any…
CVE-2025-64011 · Severity: medium · CVSS 4.3 · Published 2025-12-12
Nextcloud Server 30.0.0 is vulnerable to an Insecure Direct Object Reference (IDOR) in the /core/preview endpoint. Any authenticated user can access previews of arbitrary files belonging to other users by manipulating the fileId parameter. This allows unauthorized disclosure of sensitive data, such as text files or images, without prior sharing permissions.
No. Junglewise Threat Intelligence has no report of CVE-2025-64011 being exploited in the wild.
How severe is CVE-2025-64011?
Medium severity, with a CVSS score of 4.3, published 12 December 2025.
Which products and versions are affected?
Nextcloud Server. The advisory does not name versions.
Is there a fix for CVE-2025-64011?
No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
Am I affected by CVE-2025-64011?
Check whether you run Nextcloud Server. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.